Optics with Quantum Hall Skyrmions

TL;DR

This paper investigates the optical properties of Skyrmions in quantum Hall systems, proposing methods for their optical detection and analyzing their behavior in disordered and pure environments.

Contribution

It provides a detailed theoretical analysis of Skyrmion optical signatures and proposes experimental approaches for their detection via photoluminescence spectroscopy.

Findings

Skyrmions exhibit a unique optical signature distinguishable from electrons.

Skyrmionic excitons can have lower energy than magnetoexcitons.

Optical signatures of Skyrmions are robust in various system conditions.

Abstract

A novel type of charged excitation, known as a Skyrmion, has recently been discovered in quantum Hall systems with filling factor near \nu = 1. A Skyrmion -- which can be thought of as a topological twist in the spin density of the electron gas -- has the same charge as an electron, but a much larger spin. In this review we present a detailed theoretical investigation of the optical properties of Skyrmions. Our results provide means for the optical detection of Skyrmions using photoluminescence (PL) spectroscopy. We first consider the optical properties of Skyrmions in disordered systems. A calculation of the luminescence energy reveals a special optical signature which allows us to distinguish between Skyrmions and ordinary electrons. Two experiments to measure the optical signature are proposed. We then turn to the optical properties of Skyrmions in pure systems. We show that, just like an ordinary electron, a Skyrmion may bind with a hole to form a Skyrmionic exciton. The Skyrmionic exciton can have a lower energy than the ordinary magnetoexciton. The optical signature of Skyrmions is found to be a robust feature of the PL spectrum in both disordered and pure systems.